Comparison of Supercritical CO₂-Drying, Freeze-Drying and Frying on Sensory Properties of Beetroot

• Main Authors: Nikola Tomic, Ilija Djekic, Gerard Hofland, Nada Smigic, Bozidar Udovicki, Andreja Rajkovic
• Format: Article
• Language: English
• Published: MDPI AG 2020-08-01
• Series: Foods
• Subjects: supercritical CO₂-drying; beetroot snacks; preference mapping; mean drop analysis
• Online Access: https://www.mdpi.com/2304-8158/9/9/1201

The aim of this study was to compare the sensory quality and acceptance of dried ready-to-eat beetroot snacks as a result of different drying methods applied: supercritical CO₂-drying (scCO₂-drying), frying, and freeze-drying. Descriptive sensory analysis, quality rating (10 assessors), and consumer acceptance testing (<i>n</i> = 102) were performed. Mean overall quality scores within the range of “very good” quality were found only in non-precooked scCO₂-dried samples which were characterized by typical magenta color, low level of shape and surface deformations, pronounced brittleness and crispiness, and good rehydration during mastication. The other samples were in the range of “good” quality. The pre-cooking step before scCO₂-drying negatively influenced the sensory quality parameters, particularly appearance. Around 60% of tested consumers showed a preference for the fried and non-precooked scCO₂-dried samples. The drivers of liking were mostly related to the characteristics of the product, which was salted, fried, and crispy, with an oily and overburnt flavor, i.e., the product most similar to commercial potato chips products. Freeze-drying had a negative effect primarily on appearance and flavor. According to the sensory evaluation conducted, direct scCO₂-drying without a pre-cooking step showed itself as a promising alternative drying technology in the production of dried beetroot snacks.